Due to the increasingly wide use of portable devices which can be connected to the Internet, the bandwidth of conventional wireless transmission frequencies no longer meets user needs. To enhance the speed and performance of digital signal processing systems, beam-forming has become an important technique to the 5G mobile communication. In this regard, beam-forming is a technique related to digital signal processing and array antennas. Its operating principle lies in enabling an emitter to treat a user's position as a target signal and adjust it so that not only is a main beam aimed at the target signal by modulating the beam, but the signal is also tracked in real time. Therefore, beam-forming effectuates an adaptive smart antenna system.
The common means of adjusting the beam includes beam synthesis and beam shift, which involves adjusting the distance between an array antenna unit and an array antenna so that one of the circuits in use is a phase adjustment circuit passively fed into a network. The phase adjustment circuit passively fed into a network requires a passive network, such as a Butler matrix, which adjusts transmitted energy and phases, depending on whether to change impedance matching and the electrical length of a transmission line. However, take a microstrip planar Butler matrix as an example, it has plenty drawbacks, as described below. To increase the number of the required beams, the structural size of the microstrip planar Butler matrix has to increase, thereby adding to the difficulty in integrating the microstrip planar Butler matrix and an array antenna. Due to the way of arranging the transmission lines of the microstrip planar Butler matrix, energy in a circuit substrate is likely to keep attenuating. Therefore, the aforesaid passive network for effectuating phase shift and beam adjustment cannot be effectively applied to most circuits, not to mention that it is cost-ineffective because of excessive energy loss.
A conventional communication data transmission system relies upon the trigonometric positioning method to adjust a beam to a required position, using parameters obtained by the positioning method. But the method is restricted to positioning and directing the beam toward a specific positioning handheld device. Furthermore, variations in user habits lead to everlasting position changes. As a result, the communication data transmission system has to detect for a user's position at specific time intervals, and in consequence signal transmission ends up with a waiting time period known as “window period.” To detect a user's position anew, the system spends much time waiting for a positioning process in the course of signal transmission, not to mention that beam adjustment does not begin until the detection process ends.
As a result, the aforesaid communication transmission system has low processing efficiency and therefore fails to meet user needs, thereby having much room for improvement.